With the addition of Marillyn Hewson (Lockheed Martin) and Marissa Mayer (Yahoo!) to the roster of female CEOs, women are celebrating the milestone of having reached the highest number of women in CEO positions within the Fortune 500 -- a whopping 21 (4 percent).

Finding balance in your life and a good fit in your workplace are greater attributors to success than anything else, believes Cathy L. Williams, former CFO of Shell Canada and MBA ’77 Queen’s University.